Philippine Journal of Science
150 (6B): 1751-1763, December 2021
ISSN 0031 – 7683
Date Received: 08 Apr 2021

Vibrio and Heterotrophic Marine Bacteria Composition
and Abundance in Nutrient-enriched Kappaphycus striatus

Albaris B. Tahiluddin^1,2, Sharon N. Nuñal³, Maria Rovilla J. Luhan⁴,
and Sheila Mae S. Santander–de Leon¹*

¹Institute of Marine Fisheries and Oceanology, College of Fisheries and Ocean Sciences
University of the Philippines Visayas, Miag-ao, Iloilo 5023 Philippines
²College of Fisheries, Mindanao State University-Tawi-Tawi
College of Technology and Oceanography, Sanga-Sanga
Bongao, Tawi-Tawi 7500 Philippines
³Institute of Fish Processing Technology, College of Fisheries and Ocean Sciences
University of the Philippines Visayas, Miag-ao, Iloilo 5023 Philippines
⁴Aquaculture Department, Southeast Asian Fisheries Development Center
Tigbauan, Iloilo 5021 Philippines

*Corresponding author: sssantanderdeleon@up.edu.ph

 

ABSTRACT

Inorganic nutrient application in Kappaphycus seaweed farming has been a practice in the southern Philippines for the past years. To investigate the inorganic nutrient’s influence on the number and assemblage of Vibrio and heterotrophic marine bacteria and on the presence of ice-ice disease-inducing bacteria in Kappaphycus striatus, a field experiment was conducted using ammonium phosphate (16-20-0) fertilizer at high concentration (HC, 8.82 g L–1), low concentration (LC, 0.01 g L–1), and control (C, 0.00 g L–1). Vibrio (VCs) and heterotrophic marine bacterial counts (HMBCs) were found similar among treatments. Based on 16S rRNA gene sequencing, isolates from source K. striatus, nutrient-enriched K. striatus (HC, LC, and C), farm seawater, and fertilizer solutions were identified as Vibrio alginolyticus (three strains), V. parahaemolyticus, V. brasiliensis, V. harveyi, Gilvimarinus chinensis, and species related to Bacillus sp. ST7, Psychrobacter sp. ST8, Enterococcus sp. ST5, Oceanobacillus sp. ST9, and Paracoccus sp. ST10. Bacillus sp. ST7 and Oceanobacillus sp. ST9 were unique and only present in HC and LC. The agarolytic activity of G. chinensis, isolated from all samples, suggests that it is an ice-ice disease-causing bacterium. The microbial community dynamics of farmed K. striatus, when enriched with inorganic nutrients, may pave way in addressing the occurrence of ice-ice disease